I'm not so objective at the moment as I have a very recent ex A who blames me for everything. Even makes stuff up to hate me. I'm going to tell you at your young age, there is so much more happiness to be had and life to be lived. Don't waste it like this. Get OUT! You have no kids together. Just GO!! As sad as I am now that my relationship has ended and as sad as it makes you to think of ending yours, there is absolutely NO WAY we will remain sad forever. You will be so much happier when you heal from this.
Walking around on eggshells in fear and anxiety is not a relationship anyway. There's nothing there but a history of what once was. I have done this. Staying is just delaying the inevitable and being tortured while you wait.
I hope you find the courage sweetie.
And Welcome!!!